A combustion gas (exhaust gas) discharged from an automotive engine is discharged to the outside from the end (tail end) of a tailpipe through an exhaust manifold, a catalytic converter (that is provided directly below the exhaust manifold), a front tube, an underfloor catalytic converter, a center muffler, a main muffler, and the like that are sequentially connected to the engine (see Patent Document 1 (JP-A-2008-190371), for example).
Most of such an automotive exhaust system (exhaust pipe) (e.g., main muffler) is provided at the bottom of the automobile, and is not normally observed from the user. However, since the end (tail end) of the tailpipe that is situated at the end of the exhaust system (exhaust pipe) is exposed under the rear bumper of the automobile, the tailpipe is easily observed from the user, and significantly affects the appearance of the automobile.
Therefore, a muffler cutter is normally provided to the end of the tailpipe so that the appearance and the quality of the automobile are improved.
A high-displacement automobile has a tendency in which the volume of exhaust noise increases, and the load applied to the main muffler and the like increases. Therefore, a muffler cutter that can reduce exhaust noise that could not be absorbed by the main muffler and the like has been desired.
On the other hand, a user who has a preference for an idling sound or like may be dissatisfied if exhaust noise is merely reduced. Therefore, a muffler cutter that can achieve an excellent sound-absorbing capability and an excellent exhaust sound quality-improving capability (that have a trade-off relationship) has also been desired.